Improving the Speech Intelligibility of Adults with Down Syndrome (DS) Using the Core Vocabulary Approach

Book excerpt: The goal of the present study was to evaluate the efficacy of the Core Vocabulary approach (CVA; Dodd, Holm, Crosbie, & McIntosh, 2006) for improving speech intelligibility in an adult with DS by establishing consistent word production in order to enhance communicative competence and participation within a variety of social settings. Research indicates marked limitations in speech intelligibility in individuals with DS, including delayed and disordered articulation and inconsistent speech errors (i.e., variability in production of the same word) that continues throughout the individual’s life (Kent & Vorperian, 2013). This study evaluated the effectiveness of CVA on intelligibility by targeting reduction in variability in target word productions selected because they were functionally salient for the client. Data collection consisted of a slight adaptation to CVA, including both speech accuracy and variability measures to evaluate the effect of CVA. The following question was addressed: What are the effects of core vocabulary on the variability and accuracy of production of target words in an adult with DS? Results suggest that vowel accuracy is a relative strength in her system as compared to consonants, and two-syllable shaped words are her upper boundary. However, while accuracy measures demonstrated some slight improvement across intervention sessions, variability remained stable and did not show the same change over time. A variety of adaptations and possible future research topics are discussed.